Optimal Parking

Optimal Parking | JXNUOJ 

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describe ：

When shopping on the long street , Michael usually parks his car at a random location , Then walk to the store he needs .
Can you help Michael choose a parking place that can minimize his walking distance while shopping ？
The long street is a straight line , All positions are integers .
You pay for parking at a specific location , This position is the integer position on the long street . however , Michael doesn't want to pay for multiple parking spaces . He's strong , Don't mind carrying all your bags .
Input ：
The first line of input gives the number of test cases ,1 <= t <= 100. Each test case has two lines . The first one gives Michael The number of stores you want to go ,1 <= n <= 20, The second one gives them what they are doing in Long Street Upper n Integer positions ,0 <= xi <= 99.
Output ：
Output a line of the minimum distance Michael must walk under the best parking conditions for each test case .